Lets assume your new to catfishing. A few key points are going to be location, bait, and gear.

Location- When it comes to rivers, you are going to be looking for areas of the river that are different from the rest of the river. Some key areas are going to be deep holes, current seams, eddies, snags, and below dams. What you are looking for is places that catfish can hang out with ease (slack water) and ambush bait coming by them (faster water). Some of these places are obvious on the surface and others take awhile to learn since they are beneath the surface.

Bait- Channel Cats love a good, fresh, cut bait. I would recommend a sucker minnow for starters. You can buy them at the baitshop, cut them into chunks, and fish with them and they are very effective. The more you fish, the more you will experiment with different types of cutbait. Fresh caught suckers from the river work good, Goldeye, Mooneye, Shad, and even frogs work well. What I don't have much confidence in is prepared baits such as doughballs, blood, and stinkbait. Fresh cut works that well that I haven't resorted to other options yet.

Gear- Catfish fight harder (pound for pound) than any other fish you will encounter in Minnesota. If you think a 4lb walleye puts up a good fight on walleye gear, try catching a 4lb channel cat in a river on the same rig. You will look at catfish entirely differently after that. They are hard fighters and very fun to catch! For a minimal investment, I would look at a M or MH catfish rod (Ugly Stick Catfish would be good!) paired with a 6500C3 Abu Garcia reel!